1. Technical Field
Embodiments of the invention relate to semiconductor packages with stiffening support to provide line sockets for power delivery to electrical components installed in the sockets, and methods of fabricating semiconductor packages.
2. Description of Related Art
FIG. 1 is a cross-sectional view of a thin semiconductor package 100 built upon a coreless substrate 102 on which a package stiffener 104 is mounted on a periphery of the substrate 102 to provide stiffening support to the thin semiconductor package. Die side capacitors 106 may be arranged between a semiconductor die 108 and the stiffener 104 to deliver electrical power to the die 108 as and when required, e.g., when on-die capacitors are fully discharged. Die-side capacitors 106 are typically are soldered onto the substrate 102 which makes removal difficult.
A potential to reduce a distance (XX1) between the semiconductor die 108 and the package stiffener 104 is limited by the underfill materials 110, solder materials 112 provided to the die 108 and the die-side capacitor 106 respectively. In practice, both the underfill materials 110 and solder materials 112 should be spaced apart at least by a keep-out zone distance (X1) to reduce the risk of package or die side capacitors breakage due to thermal cycling effects of the underfill materials 110 and solder materials 112 which have different coefficients of thermal expansion (CTE). Further, a keep-out zone (X2) is also maintained between the stiffener 104 and the capacitor solder 112. The distance (XX1) between the semiconductor die 108 and the package stiffener 104, however, poses a severe limitation to reducing an overall package size (XX2) and yet translates into higher overall costs due to additional substrate area needed by the coreless substrate 102 to accommodate both the stiffener 104 and die side capacitors 106.